Melons (scientific name: Cucumis melo L.) produced by the gourd family came originally from the areas along the Niger river in Africa and then distributed from the place of origin to Central Asia (the secondary place for primeval melons) where the varieties of melon were differentiated. Melons spread therefrom to the West to become the "western melon" (referred to as "melon," hereinafter) and the one distributed to the East became the "oriental melon."
Melon is also popular in Japan and a number of different types of melons have been cultivated. However, these cultivated melons have only a sweet taste in a part of the flesh, and no cultivated melons tasting characteristically of a sour taste were known.